scholarly journals Phenylalanine hydroxylase contributes to serotonin synthesis in mice

2021 ◽  
Vol 35 (6) ◽  
Author(s):  
Alexander Mordhorst ◽  
Priyavathi Dhandapani ◽  
Susann Matthes ◽  
Valentina Mosienko ◽  
Michael Rothe ◽  
...  
Keyword(s):  
Phenylalanine Hydroxylase ◽  
Serotonin Synthesis

Dietary intake of tryptophan tied emotion-related impulsivity in humans

2019 ◽  
pp. 1-8 ◽  
Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Essential Amino Acid ◽  
Food Habits ◽  
Psychological Disorder ◽  
Serotonin Synthesis ◽  
Amino Acid Tryptophan ◽  
Pass Through ◽  
Three Factor

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.

In vitro screen of inhibitors of rat brain serotonin synthesis

1969 ◽  
Vol 47 (5) ◽  
pp. 501-506 ◽  
Author(s):  
E. G. McGeer ◽  
D. A. V. Peters
Keyword(s):  
Rat Brain ◽  
Tryptophan Hydroxylase ◽  
Inhibitory Effect ◽  
Complexing Agents ◽  
Serotonin Synthesis ◽  
Structural Requirements ◽  
Class A ◽  
Numerous Data ◽  
Comparison Of The Results

Over 700 compounds were screened at 10−4 M concentration as inhibitors of the conversion of L-tryptophan-14C to serotonin-14C in crude rat brain homogenates. Most of the compounds had little or no inhibitory effect. Those with strong inhibitory properties were tested as inhibitors of 5-hydroxytryptophan decarboxylase and, if active on the decarboxylase, were assayed as tryptophan hydroxylase inhibitors. Except for a few oxidizing and complexing agents and for some substituted p-phenylenediamines, the compounds found to inhibit tryptophan hydroxylase by >50% belonged to the three types of inhibitors already known, i.e. catechols, phenylalanine and ring-substituted phenylalanines, and 6-substituted tryptophans. The numerous data in this screen make possible some comments as to the structural requirements for activity within each class. A comparison of the results on tryptophan hydroxylase with data on tyrosine hydroxylase inhibition in similar homogenates makes it clear that two separate, if somewhat similar, enzymes are involved.

scholarly journals Phenylalanine Hydroxylase in Cultured Hepatocytes

1973 ◽  
Vol 248 (1) ◽  
pp. 223-232
Author(s):  
Donald F. Haggerty ◽  
Peggy L. Young ◽  
G. Popják ◽  
William H. Carnes
Keyword(s):  
Phenylalanine Hydroxylase ◽  
Cultured Hepatocytes

Serotonin depletion reduces both acquisition and expression of context-conditioned fear

2021 ◽  
pp. 1-8
Author(s):  
S. Melker Hagsäter ◽  
Robert Pettersson ◽  
Axel Holmäng ◽  
Elias Eriksson
Keyword(s):  
Unconditioned Stimulus ◽  
Memory Consolidation ◽  
Clinical Studies ◽  
Conditioned Fear ◽  
Sprague Dawley ◽  
Serotonin Synthesis ◽  
Synthesis Inhibitor ◽  
Serotonin Depletion ◽  
Sprague Dawley Rats ◽  
The Impact

Abstract Objective: Whereas numerous experimental and clinical studies suggest a complex involvement of serotonin in the regulation of anxiety, it remains to be clarified if the dominating impact of this transmitter is best described as anxiety-reducing or anxiety-promoting. The aim of this study was to assess the impact of serotonin depletion on acquisition, consolidation, and expression of conditioned fear. Methods: Male Sprague–Dawley rats were exposed to foot shocks as unconditioned stimulus and assessed with respect to freezing behaviour when re-subjected to context. Serotonin depletion was achieved by administration of a serotonin synthesis inhibitor, para-chlorophenylalanine (PCPA) (300 mg/kg daily × 3), (i) throughout the period from (and including) acquisition to (and including) expression, (ii) during acquisition but not expression, (iii) after acquisition only, and (iv) during expression only. Results: The time spent freezing was significantly reduced in animals that were serotonin-depleted during the entire period from (and including) acquisition to (and including) expression, as well as in those being serotonin-depleted during either acquisition only or expression only. In contrast, PCPA administrated immediately after acquisition, that is during memory consolidation, did not impact the expression of conditioned fear. Conclusion: Intact serotonergic neurotransmission is important for both acquisition and expression of context-conditioned fear.

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